Process for the optical brightening of fibrous materials made from polyacrylonitrile

ABSTRACT

FIBROUS MATERIALS MADE OF POLYMERS CONTAINING AT LEAST 85% OF POLYACRYLATONITRILE CAN BE OPTICALLY BRIGHTENED IN A SAID MATERIAL WITH A LIQUOR CONTAINING A 1-(4&#39;&#39;-B-ALKOXYETHYL SULFONYL)-PHENYL-3-B-CHLOROPHENYL-$2-PYRAZOLINE, ADJUSTING THE IMPREGNATED MATERIAL TO A LIQUOR CONTENT OF ABOUT 5 TO 120% BY WEIGHT REFERRED TO THE DRY-WEIGHT OF THE GOODS, AND HEATING IT FOR ABOUT 2 SECONDS TO 30 MINUTES TO A TEMPERATURE OF ABOUT 100 TO 150*C.

United States Patent Oflice No Claims priority, application Germany, Jan. 30, 1969, P 19 04 424.7

Int. Cl. C09k 1/02 US. Cl. 117-335 T I 11 Claims ABSTRACT OF THE DISCLOSURE Fibrous materials made of polymers containing at least 85% of polyacrylonitrile can be optically brightened in a said material with a liquor containing a 1-(4'-B-alkoxyethyl sulfonyl)-phenyl-3-p-chlorophenyl-A -pyrazoline, adjusting the impregnated material to a liquor content of about 5 to 120% by weight, referred to the dry-weight of i the goods, and heating it for about 2 seconds to 30 minutes to a temperature of about 100 to 150 C,

The present invention provides a process for the optical brightening of fibrous materials made from polyacrylonitrile.

From Belgian Pat. No. 670,161 it is known to use as optical brighteners pyrazoline compounds corresponding to the general Formula I SOs-CHs-CHz-Y-Rv I in which R stands for an aryl radical that may be substituted, more especially a phenyl radical, preferably pchlorophenyl, Y stands for an oxygen or sulfur atom and R represents an alkyl, aralkyl or phenyl radical, optionally substituted by hydroxy, alkoxy-, N,N-dialkylamino, quaternary trialkylammonium, carboxy or esterified carboxy groups. 1

According to Example 7 of the cited patent specification also fibrous materials of polyacrylonitrile may be brightened therewith. However, it appeared that the brightening effect obtainable with the compounds of the said type under the conditions stated in that patent can still be improved.

Now, it has been found that fibrous materials made from polyacrylonitrile or polymers containing at least 85% of polyacrylonitrile can be optically brightened in a particularly advantageous manner, when they are impreg-L nated with an optical brightener of Formula II in which A is a lower, optionally branched, alkylene radical, R is a lower alkyl group, R each represent a lower alkyl group which together with the nitrogen atom may form a saturated heterocyclic ring, X stands for a colorless anion and n is 1 or 2, and the impregnated fabric is adjusted to a liquor content of about 5 to referred to the weight of the goods, and heated, subsequently, for about two seconds to about 30 minutes to a temperature from about 100 to about 150 C. The heating is, preferably, achieved, with steam of about 100 to about C. It may also be advantageous to dry the impregnated fibrous material before heating or, preferably, steaming it. The described treatment is advantageously performed continuously.

The brightening effect achieved in said manner can still be enhanced when a non-ionic nitrogen containing fatty acid oxethylate and/or a quaternary condensation product of a fatty acid is added to the brightening liquor. The additives mentioned provide, when used in conjunction with the above-identified optical brighteners, a degree of whiteness of exceptional brilliance. Moreover, they exert a brightening and softening eifect on the fibre which, for example, results in an essential improvement in the later spinning Process of spinning cables.

In case the brightened fabric is to be printed simultaneously, it is advisable to subject it, after it has been padded with the optical brightener and, optionally, the said additives, to an intermediary drying at about 50 to about C. The thus dried fabric is, subsequently, printed and then heated in known manner, preferably by steaming. The heating process serves for fixing the printing ink which has been applied to the fabric. At the same time, the optical brightener padded onto the material comes into its full effect. To prevent migration of the optical brightener at drying, furthennore known thickeners such as starch ether, tragacanth, carob bean flour, crystal gum etc. may be added.

Another preferred version of carrying out the instant process consists in using the brighteners corresponding to Formula II which have a blue fluorescence of a violet hue and yield thus brightenings of a violet to reddish tint, in

Patented Sept. 12, 1972 eral Formula III in {which A, R R X and n have the meanings specified above. The compounds of Formula III show a greenishblue fluorescence and are thus able, when applied in mixture with the compounds of Formula II, to compensate the reddish tint thereof. They are advantageously added in an amount of about 0.05 to about by weight, preferably about 0.5 to about 3% by weight, referred to compound II.

The compounds of Formula III can be obtained by condensing di(p-chlorobenzoD-acetone with 4-hydrazinepheny1-,8-hydroxy-ethyl-sulfone, subsequent transformation of the fi-hydroxyethyl group viathe sulfuric acid ester into the vinylsulfone group and addition thereto of a correspondingly substituted alcohol.

The concentrations of optical brightener employed in the instant process are within the usual range. They can be easily determined by anyone skilled in the art by simple preliminary tests. As a guide-line the threshold values of about 0.1 to about 50 g. of optical brightener/l. of impregnation liquor may serve. Advantageously, the concentration of the brightener in the impregnation liquor and the liquor content are adjusted such to yield a concentration of brightener on the goods of about 0.05-to about 5% by weight. n

The following examples serve to illustrate the invention. The parts and percentages are by weight unless. otherwise stated.

EXAMPLE 1 A sliver consisting of at least 85% of polyacrylonitrile was treated with a bleaching liquor containing as the optical brightener 1 g./l. of the compound of Formula IV.

I Czlis SO; CH2 CH: O (311': CH2 N CzHs IV The pH of the solution was adjusted to 3 by means of" oxalic acid. Furthermore, 1.5 g./l. of a condensation product of stearic acid and of an addition. product of 4 mols of ethylene oxide on ammonia and, 1'g./l. of a quaternated condensation product of diethylene :triarnine. and stearic acid were added to that padding liquor. After its impregnation with the said solution, the sliver was squeezed 00? between cylinders until its moisture content, was about 100% and treated for three minutes with Sililk rated steam of 100 C.in an appropriate steamer. The. thus brightened fabric showed an excellent degree ,of whiteness which was substantially superior to that ofv theuntreated fabric and distinctly higher than obtained by V the process described in Example 7 of Belgian patent. spec1fication No. 670,161.

5 of whiteness.

A liquor containing 1.5 g./l. of the optical brightener of the Formula V SOz'CHZ-CH O-CH -CH -N CHz- C332 /CH CH3" CH2 justed to ,,3.5 by means of oxalic acid. For the spraying,

an amount'of liquor was" employedffsiifiicient to achieve mmoisturemqntent of; Saidfabriewa s. subsequently, treated fonQlO seconds with steam of .-104 C. After the treatment, thetow showed an excellent degree EX E i A fabric consisting of at least 85% v of polyacrylonitrile was impregnated with a li'quor'con'taining 2 g./l. of an optical brightener having the formula VI and-1 gf/lT'of a quaterna'ted condensatiori -produc't oi diethylenetriamine and' stearic acid. The of' the'tre a tl-l ing liquor was adjusted to 2 and the liquor, thereupon, 3 thickened by adding 10 g./l. of acommercial starch ether.

The fabric was squeezed off to a moisture content of 80%, between rollers and dried for two minutes at C.

Then it was printed in known manner with disperse dyestuffs and steamed for 20 minutes'at 103 C. The unprinted areas of the fabric showed an excellent degree of whiteness.

EXAMPLE 4 of an optical brightenerjof jthe Forrnula H and 0.05 g./l. of an optical brightener having the Formula /C a S OrCHz-CHz- O- ?H- CHZ'N CH3 CH3 VIII The pH of the solution was adjusted to 2 by means of sulfuric acid. FurtherrnOre, 2 g./l. of a quaternated condensation product of diethylene triamine and stearic acid were added to the padding liquor. The knit fabric was, after its impregnation with the said solution, squeezed off between rollers until its moisture content was about 100% and treated for 30 seconds with saturated steam of about 120 C. in an appropriate steamer. The thus brightened fabric showed an excellent degree of whiteness, substantially superior to that of the untreated goods.

We claim:

1. In the process for the optical brightening of fibrous materials of polymers containing at least 85% of acrylonitrile with a 1-(4-}8-alkoxyethyl sulfonyl)-phenyl-3-pchlorophenyl-A pyrazoline the improvement consisting of impregnating said material with a liquor containing a brightener of the formula in which A is lower alkylene, R is lower alkyl, R are lower alkyl, or together with the nitrogen a saturated heterocyclic ring, X is a colorless anion and n is l or 2, adjusting the impregnated material to a liquor content of about to about 120% by weight, referred to the weight of the good, and heating it for about 2 seconds to about 30 minutes to a temperature of about 100 to about 150 C.

2. The process as claimed in claim 1, wherein the concentration of the brightener in the impregnation liquor is 0.1 to 50 g./l.

3'. The process as claimed in claim 1, wherein the adjusting of the liquor "content is accommodated to the concentration of the brightener in the impregnation liquor to yield a concentration of the brightener on the good of 0.05 to 5% by weight, referred to the good.

4. The process as claimed in claim 1, wherein heating is achieved with steam.

5. The process as claimed in claim 1, wherein the impregnated material is dried before heating.

6. The process as claimed in claim 1, wherein the treatment is performed continuously.

7. The process as claimed in claim 1, wherein the impregnation liquor is adjusted to a pH of 2 to 4.

8. The process as claimed in claim 1, wherein the impregnation liquor contains an adjuvant selected from the group consisting of a nonionic condensation product of a fatty acid and oxethylated ammonia and a quaternary condensation product of a fatty acid and a low-molecular aliphatic polyamine.

9. The process as claimed in claim 1, wherein the impregnation liquor contains a thickener for textile printing inks.

10. The process as claimed in claim 1, wherein the impregnation liquor contains 0.05 to 10% by weight of a compound of the formula [Qua References Cited UNITED STATES PATENTS 3,357,988 12/1967 Hausermann et al. 117--33.S X

' 2,873,206 2/1959 Geigy et a1 11733.5

RALPH S. KENDALL, Primary Examiner US. Cl. X.R. 

